Bias vary trem with cathode bias?

[CitizenCain]

Is a combo like this possible to do? For some reason I'm just not wrapping my head around this.

Thanks

[Jazz P Bass]

Cathode Bias Vibrato

Nothing new under the sun.
Fender VibroChamp.
Vary the driver tube.

[CitizenCain]

Oops, forgot to say, this would be for a P-P amp. Would the Champ type circuit work if the PI was a cathodyne and you just varied the bias on that? What about a LTP?

Thanks for the push though, forgot about the V-Champ!

[BiBi]

Can't see why the type of PI matters at all. Here's a good link to bias modulation tremolo circuits: Bias Modulating Tremolo Circuits

[tubeswell]

Is a combo like this possible to do? For some reason I'm just not wrapping my head around this.

Thanks

Gibson GA17RVT

[d95err]

Just think of a cathode biased amp as fixed bias, where the bias voltage is 0V. Then connect the tremolo just like on any fixed bias amp.

[CitizenCain]

Thanks guys! I think I've got it now.

Tubeswell, that Gibson schematic put it in the light for me. Kind of tough to read at first with all the triode drawn sideways though

[ThermionicScott]

Just think of a cathode biased amp as fixed bias, where the bias voltage is 0V. Then connect the tremolo just like on any fixed bias amp.

How would you apply the tremolo signal to the grids without lifting the ground connection?

- Scott

[tubeswell]

How would you apply the tremolo signal to the grids without lifting the ground connection?

- Scott

The GA17RVT has 330k between the grid load resistors and the ground for just that purpose - replace it with a 250k pot and you have a depth control.

[Loogie]

I just spent some time with a Silvertone 1482. Check that out too. Nice trem.